@Article{SobralAbdu:1991:SoAcEf,
               author = "Sobral, Jose Humberto Andrade and Abdu, Mangalathayil Ali",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)}",
                title = "Solar activity effects on equatorial plasma bubble zonal velocity 
                         and its latitude gradient as measured by airglow scanning 
                         photometers",
              journal = "Journal of Atmospheric and Solar-Terrestrial Physics",
                 year = "1991",
               volume = "53",
               number = "8",
                pages = "729--742",
                month = "Aug.",
             keywords = "solar activity, equatorial plasma bubble, zonal velocity, 
                         airglow.",
             abstract = "Using a new mode of scanning 630-nm photometer operation the zonal 
                         velocities of ionospheric plasma depletions were measured over 
                         Cachoeira Paulista in Brasil in two east-west planes tilted 30°N 
                         and 30°S with respect to zenith. The measurements cover a time 
                         period of approximately 2 years, from January 1988 to January 
                         1990, a period marked by significant increase in solar activity of 
                         the ongoing cycle. The results have permitted a rather detailed 
                         evaluation of the local time and latitude variations in the zonal 
                         plasma bubble velocity as a function of solar activity. Although 
                         the mean trend in the velocity local time variation is a decrease 
                         from early evening to post-midnight hours, a strong tendency for 
                         velocity peak is observed near 21 LT and midnight. The velocities 
                         as well as their height (latitude) gradients show perceivable 
                         increases with solar activity represented as sunspot numbers. The 
                         present results are compared with the ambient plasma velocities 
                         measured using the Jicamarca radar by Fejer et al. (1985) J. 
                         Geophys. Res.90,12249, with that measured on board the DE 2 
                         satellite on the equatorial latitudes by Coley and Heelis (1989), 
                         J. Geophys. Res.94, 6751, and with various theoretical 
                         calculations, in an attempt to bring out the salient features of 
                         the plasma dynamics of the equatorial ionosphere.",
                 issn = "1364-6826",
                label = "7100",
             language = "en",
           targetfile = "1-s2.0-002191699190124P-main (1).pdf",
        urlaccessdate = "01 maio 2024"
}